Triple negative breast cancer is a particularly malignant and hard to treat type of the disease. At the present there are no established biomarkers and drug targets to aid the diagnosis and prognosis of triple negative breast cancer and to inform rationale- based drug discovery and treatment options. This project will utilize recently developed large-scale post-genomic methods to analyze the proteomes of triple negative breast tumors and establish quantitative protein expression profiles of node- metastatic and non-metastatic tumors. The main objective of the project is to identify and validate proteins which are specifically over expressed in metastatic triple negative breast cancer. Ten metastatic and ten non-metastatic triple negative breast tumors will be profiled at an analytical depth of more than 2,000 proteins. The differentially expressed proteins identified by this large-scale profiling will be validated by immunochemical methods and targeted mass spectrometry assays. The obtained data will provide candidate protein markers and potential drug targets that can be used to develop new, more individualized and more efficient therapies for triple negative breast cancer.